Samson 2780-1, Монтаж и эксплуатация, Страница: 33 / 52

EB 5840 EN 8-3
Servicing and conversion work
8.2 Preparation for servicing
or conversion work
1. Lay out the necessary material and tools
to have them ready for the intended
work.
2. Put the actuator out of operation (see
'Decommissioning' section).
3. Remove the actuator from the valve (see
the 'Removal' section).
To remove an actuator with "stem extends"
fail‑safe action and/or with preloaded
springs, a certain signal pressure must be
applied to the actuator (see the 'Removal'
section). Afterwards, the signal pressure
must be removed and the air supply discon‑
nected again and locked.
4. Relieve the compression from the pre‑
loaded springs. See 'Relieving the spring
compression in the actuator' in the 'Re‑
moval' section.
5. Undo the nuts and bolts on both cases
(A42, A40).
The following servicing and/or conversion
work can be performed after preparation is
completed:
− Replace the diaphragm (see sec‑
tion 8.4.1)
−
Reverse the direction of action (see sec‑
tion 8.5.1)
8.3 Mounting the actuator on
the valve after servicing or
conversion work
1. Mount the actuator and connect the air
supply (see the 'Mounting' section).
8.4 Service work
Refer to Fig. 8‑1
8.4.1 Replacing the dia-
phragm
a) Version with direction of
action "actuator stem
extends"
1. Lift off the top diaphragm case (A42)
and remove springs (A25).
2. Unscrew the collar nut (A53).
3. Remove the diaphragm plate (A39) to‑
gether with the diaphragm (A48), metal
plate (A38) and actuator stem (A1) out
of the bottom diaphragm case (A40).
4. Place a new diaphragm on the metal
plate (A38). Place on the diaphragm
plate (A39).
5. Check the sealing element on the collar
nut (A53). If necessary, renew it.
6. Apply a suitable sealant and lubricant to
the actuator stem (A1).
7. Insert the actuator stem (A1) together
with the diaphragm plate (A39), dia‑
Note